Author/Authors :
Hosseini Daghigh, Mohsen Radiation Medicine Department - Shahid Beheshti University, Tehran, Iran , Rabi Mahdavi, Seied Medical Physics Department - Tehran University of Medical Sciences, Tehran, Iran , Aghamiri, Mahmoud Radiation Medicine Department - Shahid Beheshti University, Tehran, Iran , Jaberi, Ramin Imam Khomeini Hospital - Tehran University of Medical Science, Tehran, Iran , Baghani, Hamid Reza Radiation Medicine Department - Shahid Beheshti University, Tehran, Iran , Eidi, Ramezan Radiation Medicine Department - Shahid Beheshti University, Tehran, Iran , Boroghani, Elham Physics Department - Gilan University, Rasht, Iran
Abstract :
Introduction
Interaluminal brachytherapy is one of the important methods of esophageal cancer treatment. The effect of applicator attenuation is not considered in dose calculation method released by AAPM-TG43. In this study, the effect of High-Dose Rate (HDR) brachytherapy esophageal applicator on dose distribution was surveyed in HDR brachytherapy.
Materials and Methods
A cylindrical PMMA phantom was built in order to be inserted by various sizes of esophageal applicators. EDR2 films were placed at 33 mm from Ir-192 source and irradiated with 1.5 Gy after planning using treatment planning system for all applicators.
Results
The results of film dosimetry in reference point for 6, 8, 10, and 20 mm applicators were 1.54, 1.53, 1.48, and 1.50 Gy, respectively. The difference between practical and treatment planning system results was 0.023 Gy (<2.7%), on average.
Conclusion
Due to the similar practical results for different esophageal applicators, it can be concluded that attenuation properties of applicator wall doesn't have a significant difference with water and therefore the Flexiplan treatment planning system accuracy is further confirmed
